package com.ace.core.suppoort;

import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Created by com.ace on 2018/3/9.
 */
public class HttpKit {
    public static String getIp(){
        return HttpKit.getRequest().getRemoteHost();
    }

    /**
     * 获取所有请求的值
     */

    public static Map<String, String> getRequestParameters(){
        HashMap<String, String> values = new HashMap<>();
        HttpServletRequest request = HttpKit.getRequest();
        Enumeration enums = request.getParameterNames();
        while(enums.hasMoreElements()){
            String paramName = (String) enums.nextElement();
            String paramValue = request.getParameter(paramName);
            values.put(paramName, paramValue);
        }
        return values;
    }

    /**
     * 获取HttpServletResponse
     *
     */

    public static HttpServletResponse getResponse(){
        HttpServletResponse response = ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getResponse();
        return response;
    }

    /**
     * 获取HttpServletRequest
     */

    public static HttpServletRequest getRequest(){
        HttpServletRequest request = ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest();
        return request;
    }

    /**
     * 向指定URL发送Get方法请求
     * 主要进行请求字符串的拼接，设置通用请求的属性
     */
    public static String sendGet(String url, Map<String, String> param){
        String result = "";
        BufferedReader in = null;
        String para = "";
        /*拼接参数*/
        for(String key : param.keySet()){
            para += (key + "=" + param.get(key) + "&");
        }

        if(para.lastIndexOf("&") > 0){
            para = para.substring(0, para.length() - 1);
        }

        String urlNameString = url + "?" + para;
        try {
            URL realUrl = new URL(urlNameString);
            URLConnection connection = realUrl.openConnection();
            connection.setRequestProperty("accept", "*/*");
            connection.setRequestProperty("connection", "Keep-Alive");
            connection.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            //建立实际的连接
            connection.connect();
            //获取所有响应头字段
            Map<String, List<String>> map = connection.getHeaderFields();
            //遍历所有响应头字段
            for(String key : map.keySet()){
                System.out.println(key + "--->" + map.get(key));
            }
            //定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String line;
            while((line = in.readLine()) != null){
                result += line;
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        finally{
            try{
                if(in != null){
                    in.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return result;
    }

    public static String sendPost(String url, Map<String, String> param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            String para = "";
            for (String key : param.keySet()) {
                para += (key + "=" + param.get(key) + "&");
            }
            if (para.lastIndexOf("&") > 0) {
                para = para.substring(0, para.length() - 1);
            }
            String urlNameString = url + "?" + para;
            URL realUrl = new URL(urlNameString);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 发送请求参数
            out.print(param);
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送 POST 请求出现异常！" + e);
            e.printStackTrace();
        }
        // 使用finally块来关闭输出流、输入流
        finally {
            try {
                if (out != null) {
                    out.close();
                }
                if (in != null) {
                    in.close();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        return result;
    }
}
